Fluid cooled core for electromagnetic apparatus



April 3, 1951 J. B. wADHAMs 2,547,065

FLUID COOLED CORE FOR ELECTROMAGNETIC APPARATUS Filed OCT.. 50, 1.9147

I N VEN TOR.

Patented Apr. 3, 1951 FLUID COOLED COREv FOR ELECTRO- MAGNETIC APPARATUS James B. Wadhams, Warrensville Heights, Ohio, assignor to The Ohio Crankshaft Company,

Cleveland, Ohio Application October 30, 1947, Serial No. '783,086 3 claims. (ci. 175-356) The present invention relates, as indicated, to a fluid cooled core for electro-magnetic apparatus and is well adapted to cooling cores of transformers, particularly laminated cores of transformers for high frequency current. It is adaptable to cores of many sizes but primarily to cores of the type known as E-shaped cores.

Maximum loading of a transformer, for instance, is usually limited by the temperature to which its insulation is submitted. When this insulation reaches a certain maximum temperature, application of power must be discontinued to provide a period in which excess heat in the core can be transferred therefrom by conduction or radiation. Such heating is particularly serious at high frequencies and requires that the apparatus be either loaded to only a part of its desired capacity or loaded for only a part of the time. This results in large, costly and cumbersome apparatus for continuous use.

To reduce the size and cost oi electro-magnetic apparatus having laminated cores and to increase convenience of use of such apparatus, artificial means for cooling the laminations is extremely desirable. Hollow laminations water lled in which the water is circulated in one end and out the other have heretofore been proposed for this purpose. However, with the E-shaped cores, there is provided a discontinuous path for the flow of water and dimculty has been experienced with the formation of dead pockets in the cooling lamination, particularly at the end of the center leg of the E-shaped core where poor circulation of the water was obtained and steam pockets tended to form. The present invention eliminates dead pockets in the ow of the cooling medium from one end of the laminations to the other and, in particular, forces a flow of water up one side of the center leg of the cooling lamination and down the other side.

Accordingly, the chief object of this invention has been to provide improved fluid means for cooling laminations of such apparatus. A further object has been to provide cooling means which can be readily assembled with the laminations when the core is constructed. An additional object has been to provide means for uniformly distributing the cooling elect of the cooling means. Another object has been to provide a laminated core for electromagnetic apparatus which can be constructed inexpensively and which occupies a greatly reduced space.

Another object of the invention is the provision of a cooling lamination for an E-shaped magnetic core which includes a hollow center leg having 'shownbeing of the rectangular type.

Fig.,2 is a sectional view Fig. 1. I

Fig.v 3 is an elevational view of a modied fluid cooled lamination embodying the present invention for ltransformer having E-shaped cores.

Fig. 4 is an end plan view of Fig. 3. Referring now to Fig. 1 and Fig. 2, the core a taken on line 2-2 0i.'

shown comprises three groups of lthin iron laminations I0, II and I2 separated by hollow copper plate-like chambers I4 and I5 of limited thickness which replace other groups of iron laminations and which themselves are of the same general form as the iron laminations. The core shown comprises a generally U-shaped member I'I with a straight bar or keeper I8 to complete the magnetic circuit although it may take any conventional shape. The hollow cooling plates are usually constructed of sheet copper having a thickness of the order of one thirty-second of an inch with a space therebetween usually of the order of one-eighth of an inch or less for circulation of the cooling fluid which is usually water, oil, or other liquid or may be a gas. The cooling chambers I4 and I5 are held in rm heat conducting contact with the groups of iron laminations I0, II and I2 by bolts such as 20 passing entirely through the stack of laminations. To resist the pressure applied by the bolts and to prevent the chambers from collapsing under this pressure, spacers such as 22 are inserted between the sheets of each chamber, usually near bolts 20. These spacers and the bolts are so located as not to interfere with a free circulation of the cooling fluid in each chamber.

The uid circuit through each cooling plate comprises an inlet 24, an outlet 25 and a ilexible hose 26 connecting the U-shaped member and keeper I8. This construction permits the keeper to be moved out of position so that the core can be readily inserted into the coils or windings with which it cooperates.

Figs, 3 and 4 illustrate a hollow cooling plate or chamberfor use in cooling an E-shaped core. As indicated by the arrows, the cooling iiuid enters through inlet 30 and by means of baffles 3|, 32 and 33 which lie generally centrally in each leg, is forced to ow through all legs of the E before leaving Vtheplatc ythrough outlet `34. 'These baiil'es are usually lmade of 'suicientthickness -to serve as spacers between opposite walls of the chamber to resist pressure applied in effecting the assembly of the core by bolts passing .through tubular thimbles 35.

It will be apparent to those skilled in the art that changes can be made :in the construction of the apparatus herein disclosed without departing from the scope of the following claims, which claims are for the purpose ofdening thoseiplts of the invention which differ from earlier contributions to the art.

What I claim is: v A `core forV electromagnetic Vapparatus .com-- fpri-sed of l-a plurality of lstacked magneticallypermeable laminaticns each havingiabasesection defined by -a first edge and -a -sec'ond edge and vthree parallel leg sections iextending 'from the rst edge in spaced, `parallel relationship and l having ends remote from'said vlfirst edge, a cool- `Ving 4llamina'timi "identically `shaped 'to Vsaid mag- "netic `lan-iinations and `interposed ltherebetween and having corresponding edges, said `coolinglamination being comprised of fa :pair of spaced side 'members interconnected at their edges by fan edge member and "together defining la 4hollow interior, means for circulating cooling 'duid V'Itlflrough said pooling lamination, and la partition member extending in .the vhollow interior, from the `second edge intermediate the-edges oi said :center leg substantially -to but spaced 'from lth'e end foi said center 'leg vsection whereby Acooling fluid circulated through said cooling lamination must :traverse substantially the entire "length of said center leg.

2. The combination of claim 1 wherein said other legs have partitions extending from said second edge in the hollow interior substantially to but spaced from the ends thereof, and coolingwate'rf inlet ports located adjacent the ends of said second edge, whereby cooling fluid circulated 'in all three legs must travel the .length of `each leg'twice and dead .pockets are eliminated.

3. A two-piece core for electromagnetic appak.riatus having a main winding-receiving portion having .at least .a pair of legs and a keeper portion yin abutment with the ends of said legs to provide a flux path therebetween, said portions eachzcomprising in combination a group of magnetic lairninations, a heat-conducting member lying lin contact with each group of laniinations,

each .of Vsaid .heat-conducting members comprising a Vgenerally hollow metallic member conforming generally with the laminations, and means interconnecting the interior of said conducting member associated with :said winding-receiving vportieri and the .interior :of said conductingmembei' lassociated with the keeper portion. JAMES iB. y REFERENCES -CITED The following references :are .of record vin the file lof this patent:

UNITED STATES PATENTS 

